diff --git a/dev-libs/blake3/blake3-1.5.3.ebuild b/dev-libs/blake3/blake3-1.5.3.ebuild
index 073d73e0061b5..0e7f9fe25cc96 100644
--- a/dev-libs/blake3/blake3-1.5.3.ebuild
+++ b/dev-libs/blake3/blake3-1.5.3.ebuild
@@ -3,7 +3,8 @@
 
 EAPI=8
 
-inherit cmake
+PYTHON_COMPAT=( python3_{11..13} )
+inherit cmake python-any-r1
 
 DESCRIPTION="a fast cryptographic hash function"
 HOMEPAGE="https://github.com/BLAKE3-team/BLAKE3"
@@ -13,3 +14,18 @@ S="${WORKDIR}/BLAKE3-${PV}/c"
 LICENSE="|| ( CC0-1.0 Apache-2.0 )"
 SLOT="0/0"
 KEYWORDS="~amd64 ~arm ~arm64 ~ia64 ~loong ~m68k ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86"
+IUSE="test"
+RESTRICT="!test? ( test )"
+PATCHES=( "${FILESDIR}/${PN}-1.5.3-backport-pr405.patch" )
+BDEPEND="test? ( ${PYTHON_DEPS} )"
+
+pkg_setup() {
+	use test && python-any-r1_pkg_setup
+}
+
+src_configure() {
+	local mycmakeargs=(
+		-DBLAKE3_BUILD_TESTING="$(usex test)"
+	)
+	cmake_src_configure
+}
diff --git a/dev-libs/blake3/files/blake3-1.5.3-backport-pr405.patch b/dev-libs/blake3/files/blake3-1.5.3-backport-pr405.patch
new file mode 100644
index 0000000000000..53db4816a8593
--- /dev/null
+++ b/dev-libs/blake3/files/blake3-1.5.3-backport-pr405.patch
@@ -0,0 +1,57 @@
+https://bugs.gentoo.org/935370
+https://github.com/BLAKE3-team/BLAKE3/pull/405
+
+From aad68f7f009b7e0607b3eee3b8b8e3021fa38bd7 Mon Sep 17 00:00:00 2001
+From: matoro <matoro@users.noreply.github.com>
+Date: Tue, 2 Jul 2024 19:36:45 -0400
+Subject: [PATCH] build(CMake): support running tests with ctest
+
+---
+ CMakeLists.txt | 11 +++++++++++
+ test.py        |  4 ++--
+ 2 files changed, 13 insertions(+), 2 deletions(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 3a3b232d..e778e3d7 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -168,6 +168,17 @@ else()
+   BLAKE3_DISABLE_SIMD()
+ endif()
+ 
++# cmake test support
++if (BLAKE3_BUILD_TESTING)
++  find_package(Python3 REQUIRED)
++  get_target_property(BLAKE3_SOURCES blake3 SOURCES)
++  add_executable(blake3-testing ${BLAKE3_SOURCES} main.c)
++  set_property(TARGET blake3-testing PROPERTY OUTPUT_NAME blake3)
++  target_compile_definitions(blake3-testing PRIVATE BLAKE3_TESTING=1)
++  enable_testing()
++  add_test(test_vectors "${Python3_EXECUTABLE}" "${CMAKE_CURRENT_SOURCE_DIR}/test.py" WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
++endif()
++
+ # cmake install support
+ install(FILES blake3.h DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+ install(TARGETS blake3 EXPORT blake3-targets)
+diff --git a/test.py b/test.py
+index 98b1c3df..2eb1f07e 100755
+--- a/test.py
++++ b/test.py
+@@ -2,7 +2,7 @@
+ 
+ from binascii import hexlify
+ import json
+-from os import path
++from os import getcwd, path
+ import subprocess
+ 
+ HERE = path.dirname(__file__)
+@@ -11,7 +11,7 @@
+ 
+ 
+ def run_blake3(args, input):
+-    output = subprocess.run([path.join(HERE, "blake3")] + args,
++    output = subprocess.run([path.join(getcwd(), "blake3")] + args,
+                             input=input,
+                             stdout=subprocess.PIPE,
+                             check=True)